2011-02-09 03:53:27

by Jayson R. King

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Subject: 2.6.27.58-rc1 build error Re: [PATCH 21/23] hvc_console: Fix race between hvc_close and hvc_remove

drivers/char/hvc_console.c: In function 'hvc_open':
drivers/char/hvc_console.c:315: error: implicit declaration of function
'tty_kref_get'
drivers/char/hvc_console.c:324: warning: assignment makes pointer from
integer without a cast
drivers/char/hvc_console.c:341: error: implicit declaration of function
'tty_kref_put'
drivers/char/hvc_console.c: In function 'hvc_poll':
drivers/char/hvc_console.c:558: warning: assignment makes pointer from
integer without a cast
drivers/char/hvc_console.c: In function 'hvc_remove':
drivers/char/hvc_console.c:759: warning: assignment makes pointer from
integer without a cast

I don't see a tty_kref_get or tty_kref_put on 2.6.27. Those functions
first appeared in 2.6.28.

Jayson


2011-02-09 05:52:30

by Willy Tarreau

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Subject: Re: [stable] 2.6.27.58-rc1 build error Re: [PATCH 21/23] hvc_console: Fix race between hvc_close and hvc_remove

On Tue, Feb 08, 2011 at 09:20:42PM -0600, Jayson R. King wrote:
> drivers/char/hvc_console.c: In function 'hvc_open':
> drivers/char/hvc_console.c:315: error: implicit declaration of function
> 'tty_kref_get'
> drivers/char/hvc_console.c:324: warning: assignment makes pointer from
> integer without a cast
> drivers/char/hvc_console.c:341: error: implicit declaration of function
> 'tty_kref_put'
> drivers/char/hvc_console.c: In function 'hvc_poll':
> drivers/char/hvc_console.c:558: warning: assignment makes pointer from
> integer without a cast
> drivers/char/hvc_console.c: In function 'hvc_remove':
> drivers/char/hvc_console.c:759: warning: assignment makes pointer from
> integer without a cast
>
> I don't see a tty_kref_get or tty_kref_put on 2.6.27. Those functions
> first appeared in 2.6.28.

Oh indeed, and the ->kref struct member did not even exist in 2.6.27.
Let's drop the patch then, we don't want to add the kref everywhere,
it would have to be ported to other users.

Thanks!
Willy

2011-02-09 09:40:54

by Alan

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Subject: Re: 2.6.27.58-rc1 build error Re: [PATCH 21/23] hvc_console: Fix race between hvc_close and hvc_remove

On Tue, 08 Feb 2011 21:20:42 -0600
"Jayson R. King" <[email protected]> wrote:

> drivers/char/hvc_console.c: In function 'hvc_open':
> drivers/char/hvc_console.c:315: error: implicit declaration of function
> 'tty_kref_get'
> drivers/char/hvc_console.c:324: warning: assignment makes pointer from
> integer without a cast
> drivers/char/hvc_console.c:341: error: implicit declaration of function
> 'tty_kref_put'
> drivers/char/hvc_console.c: In function 'hvc_poll':
> drivers/char/hvc_console.c:558: warning: assignment makes pointer from
> integer without a cast
> drivers/char/hvc_console.c: In function 'hvc_remove':
> drivers/char/hvc_console.c:759: warning: assignment makes pointer from
> integer without a cast
>
> I don't see a tty_kref_get or tty_kref_put on 2.6.27. Those functions
> first appeared in 2.6.28.

Correct - for 2.6.27 I don't think you *can* make the tty layer
non-exploitable without a major backport

Alan

2011-02-09 10:34:14

by Willy Tarreau

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Subject: Re: [stable] 2.6.27.58-rc1 build error Re: [PATCH 21/23] hvc_console: Fix race between hvc_close and hvc_remove

On Wed, Feb 09, 2011 at 09:44:34AM +0000, Alan Cox wrote:
> On Tue, 08 Feb 2011 21:20:42 -0600
> "Jayson R. King" <[email protected]> wrote:
>
> > drivers/char/hvc_console.c: In function 'hvc_open':
> > drivers/char/hvc_console.c:315: error: implicit declaration of function
> > 'tty_kref_get'
> > drivers/char/hvc_console.c:324: warning: assignment makes pointer from
> > integer without a cast
> > drivers/char/hvc_console.c:341: error: implicit declaration of function
> > 'tty_kref_put'
> > drivers/char/hvc_console.c: In function 'hvc_poll':
> > drivers/char/hvc_console.c:558: warning: assignment makes pointer from
> > integer without a cast
> > drivers/char/hvc_console.c: In function 'hvc_remove':
> > drivers/char/hvc_console.c:759: warning: assignment makes pointer from
> > integer without a cast
> >
> > I don't see a tty_kref_get or tty_kref_put on 2.6.27. Those functions
> > first appeared in 2.6.28.
>
> Correct - for 2.6.27 I don't think you *can* make the tty layer
> non-exploitable without a major backport

So unless the bug is critical (I don't think it is), I'd rather avoid
a major backport at this stage.

Willy